TWI642959B - Method and apparatus for measuring electric quantity of battery - Google Patents

Abstract

The invention provides a method and a device for estimating the amount of electricity of a battery. The device includes a battery state measurement module, a coulomb calculation, and a calculation module. The battery status measurement module is used to monitor the battery status of the battery. The Coulomb meter measures the output of the battery to obtain the Coulomb measurement. The calculation module is coupled to the battery state measurement module and the coulomb meter to receive the battery state and the coulomb measurement value, and the calculation module queries the comparison table according to the battery state to obtain the battery power estimation value, and dynamically determines the weight value according to the battery state, and The battery power estimate and the coulomb meter value are adjusted according to the weight value to calculate the battery power display value of the battery.

Description

Battery power estimation method and device

The present invention relates to a battery measurement, and more particularly to a battery estimation method and apparatus.

With the advancement of technology and the convenience it brings, people are gradually unable to break away from electronic devices (such as mobile phones, tablets, personal computers, etc.) in their lives or work. In addition, with the advancement of technologies in various components (eg, processors, screens, communication components, cameras, etc.) in electronic devices, manufacturers need to increase battery capacity in electronic devices or reduce battery power consumption to increase electronics. The endurance of the device. The display value of the battery power will be an important indicator for the user to evaluate the effectiveness or use of the electronic device.

In general, electronic devices typically use a voltage look-up table to estimate battery capacity (charge display value). Figure 1 is a graph showing the relationship between battery voltage and power. Here, the battery power can be expressed by a state of charge (SOC) (ie, the horizontal axis of FIG. 1), and the unit is a percentage. The vertical axis of Figure 1 is the battery voltage, which The unit is volts. Referring to FIG. 1, in the flat voltage region of the battery (for example, the charge state is between 30% and 80%), when the voltage reading method is used to estimate the battery capacity, the error of the micro voltage measurement will cause serious Battery power display value error. In addition, the estimation of the battery power will cause the battery voltage and the state of charge diagram to fluctuate violently with the discharge state of the battery.

The invention provides a battery power estimation method and a battery power estimation device, thereby improving the accuracy of returning battery power.

The present invention provides a battery power estimation method, the power estimation method includes: querying a comparison table according to a battery state of the battery to obtain an estimated battery power; and measuring a battery output by using a battery to obtain a Coulomb measurement value; The weight value is dynamically determined according to the battery state; the battery power estimation value and the Coulomb measurement value are adjusted according to the weight value to calculate the battery power display value of the battery.

In an embodiment of the invention, the battery state includes one or a combination of a voltage value, a current value, and a temperature value, and the step of dynamically determining the weight value according to the battery state includes: when the voltage value, the current value, or the temperature When the change of the value occurs, the weight value is adjusted according to the change of the voltage value, the current value or the temperature value.

In an embodiment of the invention, the step of adjusting the weight value according to the change of the voltage value, the current value or the temperature value comprises: dynamically selecting the corresponding weight table from the plurality of weight tables according to the change of the temperature value. The corresponding weight table is queried according to the voltage value of the battery to obtain a weight value.

In an embodiment of the invention, the weight value includes a coulomb weight value and a table weight value, and the step of adjusting the weight value according to the change of the voltage value, the current value or the temperature value comprises: when the battery power estimated value When the value is less than the threshold, the weight value is adjusted so that the table weight value becomes larger as the battery power estimate becomes smaller, or the Coulomb weight value becomes smaller as the battery power estimate becomes smaller.

In an embodiment of the invention, the step of adjusting the weight value according to the change of the voltage value, the current value or the temperature value comprises: setting the table weight value to a specific gravity value when the battery power estimated value is greater than the threshold value.

In an embodiment of the invention, the weight value includes a coulomb weight value and a table weight value, and the step of adjusting the battery power estimated value and the coulomb meter value according to the weight value to calculate the battery power display value comprises: calculating the battery power. The first product of the estimated value and the table weight value. Calculate the second product of the Coulomb metering value and the Coulomb weighting value. The sum of the first product and the second product is calculated to obtain a battery power display value.

In an embodiment of the invention, the step of querying the comparison table according to the battery status to obtain the battery power estimated value comprises: determining whether the battery is in a charging state according to the current value.

In another aspect, the present invention provides a battery power estimation device, which includes a battery state measurement module, a coulomb calculation, and a calculation module. The battery status measurement module is used to monitor the battery status of the battery. The Coulomb meter measures the output of the battery to obtain the Coulomb measurement. The calculation module is coupled to the battery state measurement module and the coulomb meter to receive the battery state and the coulomb measurement value, and the calculation module queries the comparison table according to the battery state to obtain the battery power estimation value, and dynamically determines the weight according to the battery state. The value, and the battery power estimate and the Coulomb meter value are adjusted according to the weight value to calculate the battery power display value of the battery.

In an embodiment of the invention, the battery state includes one or a combination of a voltage value, a current value, and a temperature value, and when a change in the voltage value, the current value, or the temperature value occurs, the calculation module is based on the voltage value. The current value or the change in the temperature value adjusts the weight value.

In an embodiment of the invention, the computing module dynamically selects a corresponding weight table from the plurality of weight tables according to the change of the temperature value, and the computing module queries the corresponding weight table according to the voltage value of the battery to obtain a weight value.

In an embodiment of the present invention, the corresponding weight table carries a relationship between a voltage value, a coulomb weight value, and a table weight value; and when the voltage value is smaller, the Coulomb weight value is smaller, or the table weight value is checked. The bigger.

In an embodiment of the invention, the weight value includes a coulomb weight value and a table weight value; when the voltage value indicates that the battery power estimated value is less than a critical value, the calculation module adjusts the weight value to enable the table lookup The weight value increases as the battery charge estimate becomes smaller, or the Coulomb weighted value decreases as the battery charge estimate becomes smaller.

In an embodiment of the invention, when the change in the voltage value indicates that the battery power estimated value is greater than the threshold value, the calculation module sets the look-up table weight value to the specific gravity value.

In an embodiment of the invention, the weight value includes a Coulomb weight value and a table weight value; the calculation module calculates a first product of the battery power estimated value and the table weight value, and calculates a Coulomb meter value and a Coulomb weight. The second product of the value, and the calculation The sum of the first product and the second product to obtain a battery power display value.

In an embodiment of the invention, the temperature value includes an ambient temperature value or a temperature value of the battery.

In an embodiment of the invention, the computing module determines whether the battery is in a charging state according to a current value.

Based on the above, the battery estimation method and device according to the embodiment of the present invention can dynamically determine the weight value according to the battery state of the battery, and adjust the battery power estimation value and the Coulomb measurement value according to the weight value, thereby improving the battery power display value. The precision.

The above described features and advantages of the invention will be apparent from the following description.

20‧‧‧Battery

200‧‧‧Battery power estimation device

210‧‧‧Battery Status Measurement Module

230‧‧ ‧ Coulomb

250‧‧‧Computation Module

270‧‧‧Power Return Module

290, adjust_table‧‧‧ weight table

S310~S370, S410~S490‧‧‧ steps

510~590‧‧‧ Code

610, 710‧‧‧ actual electricity

630, 730‧‧‧ battery power display value according to an embodiment of the present invention

650, 750 ‧ ‧ the power of the know-how

670, 770‧‧‧ power error of the embodiment of the invention

690, 790‧‧ ‧ power error of conventional technology

Current‧‧‧current value

Voltage‧‧‧voltage value

Temperature‧‧‧temperature value

Look_up_table‧‧‧Compare table function

Table_rsoc‧‧‧Battery power estimate

Last_rsoc‧‧‧Returned power

Cc_rsoc‧‧‧ Coulomb measurement

Delta_cc‧‧・Cullen meter temperature compensation function

Fcc‧‧‧All battery power

Weight_cc‧‧·Cullen weighted value

Weight_table‧‧‧Check weight value

Rsoc‧‧‧ battery display value

Figure 1 is an example of a graph of battery voltage versus charge.

2 is a block diagram showing the circuit of a battery power estimating device according to an embodiment of the invention.

3 is a flow chart illustrating a method for estimating a power level of a battery in accordance with an embodiment of the present invention.

4 is an example of a flow chart illustrating a battery charge estimation.

FIG. 5 is an example of a pseudo code illustrating a battery power estimation.

6A and 6B are simulation diagrams of battery power display values in accordance with an embodiment of the present invention.

7A and 7B are simulation diagrams of battery power display values in accordance with an embodiment of the present invention.

2 is a block diagram showing the circuit of the battery power estimating device 200 in accordance with an embodiment of the present invention. Referring to FIG. 2 , the battery power estimating device 200 includes a battery state measuring module 210 , a coulomb counter 230 , a computing module 250 , a power return module 270 , and a weight table 290 .

According to different design requirements, the battery state measurement module 210 may include a battery voltage measurement module, a temperature measurement module, a current measurement module, and/or other battery state sensing/measuring circuits. The battery state measurement module 210 is configured to monitor the battery state of the battery 20, wherein the battery state includes one or a combination of a voltage value, a current value, and a temperature value. The temperature values include ambient temperature values and/or temperature values of the battery 20, depending on various design requirements. The coulomb counter 230 is, for example, a coulomb counter, and the coulomb meter value of the battery 20 is obtained by integrating the current flowing in/out of the battery. For example, the coulomb counter 230 can be used to measure the output power (discharge amount) of the battery 20 to obtain a coulomb measurement value.

The calculation module 250 is coupled to the battery state measurement module 210 and the coulomb counter 230 to receive the battery state and the coulomb measurement value. Computing module 250 may include a central processing unit (or central processing unit), a microprocessor, a microcontroller, a chipset (eg, a south bridge wafer), and/or other operational circuitry. Firmware and/or software can run on computational models Group 250. The firmware may be a Basic Input/Output System (BIOS). The software may be an operating system (OS), a driver, an application, and/or other software.

According to different design requirements, the power return module 270 may include a screen, a speaker, a light emitting diode (LED), etc., which display a battery power display value by image, image, text, sound, or brightness. element. In other embodiments, the battery power estimating device 200 can also transmit a digital or analog signal (battery power display value) to the next processing circuit or the external electronic device through the power return module 270 component. The weight table 290 can be stored in a storage unit (eg, a memory, a hard disk, etc.) of the battery power estimation device 200, wherein the weight table can carry a relationship between a voltage value, a coulomb weight value, and a table weight value. In some embodiments, the storage unit of the weighted form 290 may be a memory, a cache, or a register embedded in the computing module 250. In other embodiments, the storage unit of the weight-bearing table 290 may also be a memory disposed outside the computing module 250. According to different design requirements, the storage unit of the weight table 290 may be a dynamic random access memory (DRAM), a static random access memory (SRAM), or an Volatile memory (VM) or non-volatile memory (NVM).

3 is a flow chart illustrating a method for estimating a power level of a battery in accordance with an embodiment of the present invention. Referring to FIG. 3, the battery power estimation method of the embodiment is applicable to FIG. 2 . Battery charge estimating device 200. Hereinafter, the battery estimation method of the battery according to the embodiment of the present invention will be described with reference to various components or modules in the battery power estimation device 200. The various processes of the method can be adjusted accordingly according to the implementation situation, and are not limited thereto.

In step S310, the calculation module 250 queries the comparison table according to the battery status of the battery 20 to obtain the battery power estimation value. Specifically, the battery power estimating device 200 can be connected to the battery 20 to be tested, and the battery state measuring module 210 can obtain the battery state including one or a combination of a voltage value, a current value, and a temperature value. The calculation module 250 compares the obtained battery status with a comparison table, for example, the storage unit stored in the battery power estimation device 200. The comparison table carries one of the voltage value, the current value and the temperature value or a combination thereof and the battery power estimation value, and the calculation module 250 can obtain the battery power estimation value according to the comparison result. In other embodiments, the operation details of the "computation module 250 according to the battery state query comparison table of the battery 20" can be converted into the battery power of the battery 20 by referring to the conventional "voltage-electricity comparison table". estimated value.

It should be noted that, in an embodiment, before the step S310, the calculation module 250 can determine whether the battery 20 is in a charging state according to the current value of the battery 20 obtained by the battery state measurement module 210. If the calculation module 250 determines that the battery 20 is in the charging state, step S310 is not performed. On the other hand, if the calculation module 250 determines that the battery 20 is in a non-charged state (for example, a discharge state), the process proceeds to step S310.

In step S330, the coulomb counter 230 measures the output power of the battery 20 to obtain the coulomb measurement value. In some embodiments, the coulomb counter 230 obtains a coulomb metrology For a detailed description of the value, please refer to the description of the coulomb counter 230 in FIG. 2 above, and details are not described herein again. In other embodiments, the operation details of the "coulomb meter 230 measures the output power of the battery 20" can refer to the related operations of the conventional "Coulomb measurement battery". In the embodiment shown in FIG. 3, step S310 is completed and then step S330 is performed. In some other embodiments, step S310 may be performed after step S330 is completed. In still other embodiments, step S310 and step S330 can be performed simultaneously.

In step S350, the calculation module 250 dynamically determines the weight value according to the battery state. In this embodiment, when a change in voltage value, current value, or temperature value occurs, the calculation module 250 adjusts the weight value according to the change in the voltage value, the current value, or the temperature value. In the embodiment shown in FIG. 3, step S330 is completed and then step S350 is performed. In some other embodiments, step S330 may be performed after step S350 is completed. In still other embodiments, step S350 and step S330 can be performed simultaneously.

In an embodiment, the computing module 250 can dynamically measure a temperature value (eg, a temperature value of the battery 20 or an ambient temperature value) via the battery state measurement module 210. The computing module 250 can also dynamically measure the voltage value of the battery 20 via the battery state measurement module 210. Based on the change in the temperature value, the calculation module 250 can dynamically select a corresponding weight table from a plurality of weight tables. The calculation module 250 queries the corresponding weight table according to the voltage value of the battery 20 to obtain a weight value. In this embodiment, the corresponding weight table carries the relationship between the voltage value, the coulomb weight value, and the table weight value. When the voltage value is small, the Coulomb weight value is smaller, or the table weight value is larger. The weight value includes a coulomb weight value and a table weight value.

For example, Tables (1) to (3) are the corresponding weights corresponding to different temperature values. form. Referring to Table (1), Table (1) is a corresponding weight table in which the temperature value measured by the battery state measuring module 210 is less than 15 degrees Celsius (°C). In Table (1), the Coulomb weighted value decreases as the voltage value decreases, and the look-up table weight value increases as the voltage value decreases. Tables (2) and (3) are similar and will not be repeated here. In an application example, when the temperature value measured by the battery state measurement module 210 (the temperature value of the battery 20 or the ambient temperature value) is 25 degrees Celsius (° C.), the calculation module 250 selects according to the change of the temperature value. Table (2) serves as the corresponding weight table. Assuming that the voltage value of the battery 20 measured by the battery state measurement module 210 is 4000 millivolts (mV), the calculation module 250 adjusts the Coulomb weight value to 60%, and adjusts the table weight value to 40%. .

It should be noted that, in applying the embodiments of the present invention, the relationship between the voltage value in the weight table, the coulomb weight value, and the table weight value may be adjusted according to design requirements. The Coulomb weighted value can increase as the voltage value decreases, and the table weight value can also decrease as the voltage value decreases. In other embodiments, one of the coulomb weight or table weight values does not change with the voltage value (eg, maintains a fixed value (eg, 50%, 60%, etc.)) while the other with the voltage value Change with change. The sum of the Coulomb weight value and the table weight value shown in the above-mentioned Tables (1) to (3) are 100%, but may not be limited to the other embodiments. For example, in other embodiments, the sum of the coulomb weight value and the table weight value may also be 80%, 120%, 150%, etc., and the invention is not limited.

In other embodiments, when the battery power estimate is greater than a threshold, the calculation module 250 may not adjust the weight value; when the change in the voltage value indicates that the battery power estimate is less than a threshold (eg, 10%, 20) The calculation module 250 adjusts the weight value when %, etc.). The weight value includes the Coulomb weight value and the table weight value. When the change in the voltage value indicates that the battery power estimate is less than a threshold (eg, 10%, 20%, etc.), the calculation module 250 may cause the look-up table weight value to vary with the battery power estimate. Smaller and larger, and/or make the Coulomb weighted value smaller as the battery charge estimate becomes smaller. When the change in the voltage value indicates that the battery power estimate is greater than the threshold, the calculation module 250 may set the look-up weight value to a static weight value (eg, 0, 20%, 40%, etc.). For example, when the change in the voltage value indicates that the battery power estimate is greater than 30%, the calculation module 250 sets the lookup table weight value to a fixed value of 30% and sets the coulomb weight value to a fixed value of 80%. When the change in voltage value indicates that the battery power estimate is 20%, the calculation module 250 sets the lookup table weight value to 50% and sets the Coulomb weight value to 50%. When the change in the voltage value indicates that the estimated battery power is 10%, the calculation module 250 sets the table weight value to 70% and sets the Coulomb weight value to 30%.

In step S370, the calculation module 250 adjusts the battery power estimation value and the coulomb measurement value according to the weight value to calculate the battery power display value of the battery 20. In one embodiment, the calculation module 250 calculates a first product of the battery power estimate and the table weight value, calculates a second product of the Coulomb meter value and the Coulomb weight value, and calculates a sum of the first product and the second product. To get the battery power display value. For example, assume an estimated battery value of 80%, a table weight of 30%, a Coulomb scale of 75%, and a Coulomb weight of 70%. After calculation by the calculation module 250, the first product is 80%*30%=24%, the second product is 75%*70%=52.5%, and the battery power display value is 80%*30%+75%*70. %=76.5%. Then, the calculation module 250 can report the battery power display value by the power return module 270.

4 is an example of a flow chart illustrating a battery charge estimation. Referring to FIG. 4, the calculation module 250 starts to perform the power estimation of the battery 20 (step S410), and first It is judged whether or not the battery 20 is in a discharged state (step S420). If the battery is not in a discharged state, the calculation module 250 ends the battery level estimation of the battery 20 (step S490). On the other hand, if the battery 20 is in a discharged state, the calculation module 250 reads the battery state (eg, voltage value, current value, and/or temperature value) of the battery 20 via the battery state measurement module 210 in step S430. The coulomb counter 230 takes the coulomb measurement value of the battery 20 during discharge. Step S430 can refer to the related description of step S330 shown in FIG.

The calculation module 250 obtains the battery power estimation value according to the battery state (for example, the voltage value, the current value, and/or the temperature value) in step S450. Step S450 can refer to the related description of step S310 shown in FIG. The computing module 250 can calculate the weight value using the battery status (eg, voltage value, current value, and/or temperature value) in step S460. Step S460 can refer to the related description of step S350 shown in FIG. In step S470, the calculation module 250 may combine/mix the battery power estimation value with the coulomb measurement value according to the calculated weight value to obtain the battery power display value. Step S470 can refer to the related description of step S370 shown in FIG. Next, the calculation module 250 reports the battery power display value through the power return module 270 (step S480), and ends the power estimation (step S490).

In addition, the battery power estimation method of the embodiment of the present invention can also be used as a code format, and the code is stored in the storage unit of the battery power estimation device 200, and the calculation module 250 can load the code to execute Battery power estimation method. For example, FIG. 5 is an example of a code illustrating a battery power estimation. Referring to FIG. 5, the code 510 determines whether the battery is in a charging state, where current represents the current value of the battery state. If the battery is in a charged state, leave the code for this function. The code 520 is compared with the comparison table according to the battery state, wherein voltage is the voltage value of the battery state, temperature is the temperature value, and the voltage value, the current value and the temperature value are input into the comparison table function (ie, look_up_table), that is, A battery charge estimate (ie, table_rsoc) can be obtained. The code 550 estimates the Coulomb measurement value (ie, cc_rsoc) by the amount of power measured by Coulomb and the previously reported battery power (eg, the previous Coulomb or previous battery display) (ie, last_rsoc). ). Among them, the temperature value is input into the coulomb temperature compensation function (ie, delta_cc), and fcc represents the total power of the current battery. The code 570 is compared with a three-dimensional weight table (ie, adjust_table[voltage][current][temperature] by using the voltage value "voltage" of the battery state, the current value "current", and the temperature value "temperature". To obtain the Coulomb weighted value (ie, weight_cc) and the lookup table weight value (ie, weight_table). The code 580 calculates the battery power display value (ie, rsoc) according to the Coulomb weight value, the table weight value, the Coulomb meter value, and the battery power estimated value, and the code 590 is the battery power display value calculated by the code 580. Divide by the sum of the Coulomb weighted value and the table weight value to obtain the final battery power display value.

6A and 6B are simulation diagrams of battery power display values in accordance with an embodiment of the present invention. When the change in the voltage value indicates that the estimated battery power is greater than 20%, the calculation module 250 sets the lookup table weight value to 0, so the second product will be used as the battery power display value. If the Coulomb weight value is 100%, the calculation module 250 will completely calculate the Coulomb measurement value as the battery power display value. After the estimated battery power is less than 20%, the calculation module 250 gradually increases the table weight value. Please refer to Figure 6A, this model The battery power display value 630 of the example gradually approaches the actual power level 610 after being less than 20%. Referring to FIG. 6B, the power error between the battery power display value 630 and the actual power amount 610 of this example also gradually decreases. The battery power display value 630 estimated by the embodiment of the present invention is closer to the actual power amount 610 than the power 650 of the prior art.

7A and 7B are simulation diagrams of battery power display values in accordance with an embodiment of the present invention. The difference from FIG. 6A and FIG. 6B is that, in this example, when the change in the voltage value indicates that the battery power estimated value is greater than 10%, the calculation module 250 sets the table lookup weight value to 0, and thus will be completely second. The product is used as the battery power display value, or the coulomb measurement value is calculated as the battery power display value. After the estimated battery power is less than 10%, the calculation module 250 gradually increases the table weight value. Referring to FIG. 7A, the battery power display value 730 of this example gradually approaches the actual power level 710 after less than 10%. Referring to FIG. 7B, the power error between the battery power display value 730 and the actual power source 710 of this example also gradually decreases.

In summary, the computing module of the present invention dynamically adjusts the weight value according to one or a combination of the voltage value, the current value, and the temperature value in the current battery state, to adjust the battery power estimated value and the Coulomb measurement value to obtain Battery level display value. Thereby, it is possible to improve the serious power error caused by the flat voltage region of the voltage in the voltage meter reading method, and thereby improve the accuracy of the battery estimation.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

Claims (18)

A battery power estimation method includes: querying at least one comparison table according to a battery status of the battery to obtain a battery power estimation value; and measuring a battery output quantity by a Coulomb measurement to obtain a Coulomb measurement value; Determining a weight value according to at least a temperature value included in the battery state; and adjusting the battery power estimated value and the Coulomb metering value according to the weight value to calculate a battery power display value of the battery. The battery power estimation method according to claim 1, wherein the battery state includes one of a voltage value, a current value, and the temperature value, or a combination thereof, and at least according to the battery state The step of dynamically determining the weight value includes: adjusting the weight value according to the voltage value, the current value, or the change in the temperature value when the voltage value, the current value, or the change in the temperature value occurs. The method for estimating a quantity of a battery according to the second aspect of the invention, wherein the step of adjusting the weight value according to the voltage value, the current value or the temperature value comprises: changing according to the temperature value A corresponding weight table is dynamically selected from the plurality of weight tables; the corresponding weight table is queried according to the voltage value of the battery to obtain the weight value. The battery power estimation method according to claim 3, wherein the corresponding weight table carries a relationship between the voltage value, a coulomb weight value and a look-up table weight value; and when the voltage value is smaller, The smaller the coulomb weight value, or the larger the table weight value. The battery power estimation method according to claim 3, wherein the weight value includes a coulomb weight value and a look-up table weight value, and the voltage value, the current value or the temperature value is The step of adjusting the weight value includes: adjusting the weight value when the battery power estimation value is less than a threshold value, so that the table weight value is larger as the battery power estimation value becomes smaller, or The coulomb weighting value is smaller as the battery power estimate becomes smaller. The method for estimating a power quantity of a battery according to claim 5, wherein the step of adjusting the weight value according to the voltage value, the current value or the temperature value comprises: when the battery power estimated value is greater than At the critical value, the look-up table weight value is set to a specific gravity value. The battery power estimation method according to claim 3, wherein the weight value includes a coulomb weight value and a look-up table weight value, and the battery power estimation value and the coulomb are adjusted according to the weight value. The measuring value to calculate the battery power display value comprises: calculating a first product of the battery power estimated value and the look-up table weight value; calculating a second product of the coulomb metering value and the coulomb weighting value; and calculating The sum of the first product and the second product to obtain the battery power display value. The method for estimating the amount of electricity of a battery according to claim 2, wherein the temperature value comprises an ambient temperature value or a temperature value of the battery. The method for estimating a power quantity of a battery according to the second aspect of the invention, wherein the step of querying the comparison table according to the battery status to obtain the battery power estimated value comprises: determining whether the battery is in a charging state according to the current value. . A battery power estimating device includes: a battery state measuring module for monitoring a battery state of the battery; a coulomb meter for measuring the output power of the battery to obtain a Coulomb metering value; The group is coupled to the battery state measurement module and the coulomb counter to receive the battery state and the coulomb measurement value, and the calculation module queries at least one comparison table according to the battery state to obtain a battery power estimation value, according to the A weight value included in the battery state dynamically determines a weight value, and the battery power estimated value and the coulomb meter value are adjusted according to the weight value to calculate a battery power display value of the battery. The battery power estimation device of claim 10, wherein the battery state comprises one of a voltage value, a current value, and the temperature value, or a combination thereof, and when the voltage value, the current value, or the When the change of the temperature value occurs, the calculation module adjusts the weight value according to the voltage value, the current value or the change of the temperature value. The battery power estimation device of claim 11, wherein the calculation module dynamically selects a corresponding weight table from the plurality of weight tables according to the change of the temperature value, the calculation module is configured according to the battery Voltage value query the corresponding right Re-table the table to get the weight value. The battery power estimating device according to claim 12, wherein the corresponding weight table carries a relationship between the voltage value, a coulomb weight value and a look-up table weight value; and when the voltage value is smaller, the The smaller the Coulomb weight value, or the larger the table weight value. The battery power estimating device according to claim 12, wherein the weight value includes a coulomb weight value and a look-up table weight value; when the change in the voltage value indicates that the battery power estimated value is less than a critical value The calculation module adjusts the weight value such that the lookup table weight value becomes larger as the battery power estimate becomes smaller, or causes the coulomb weight value to become smaller as the battery power estimate becomes smaller. small. The battery power estimation device of claim 14, wherein the calculation module sets the table weight value to a specific gravity when the change in the voltage value indicates that the battery power estimated value is greater than the threshold value. value. The battery power estimation device of claim 12, wherein the weight value comprises a coulomb weight value and a look-up table weight value; the calculation module calculates the battery power estimation value and the table weight value a first product, a second product of the coulomb meter value and the coulomb weight value is calculated, and a sum of the first product and the second product is calculated to obtain the battery power display value. The battery power estimating device according to claim 11, wherein the temperature value comprises an ambient temperature value or a temperature value of the battery. The battery power estimating device according to claim 11, wherein the calculating module determines whether the battery is in a charging state according to the current value.